Midtrimester hemoperitoneum caused by placenta percreta in association with elevated maternal serum alpha-fetoprotein level.

We report a case of hemoperitoneum in the second trimester due to placenta percreta which was associated with an elevated maternal serum alpha-fetoprotein. A 29-year-old woman, gravida 4, para 1-0-2-1, was seen at 17 weeks' gestation with an acute abdomen. Maternal serum alpha-fetoprotein in a sample drawn 1 week previously revealed a value of 5.0 multiples of the median. At laparotomy, placenta percreta was discovered. This case of placenta percreta diagnosed in the second trimester was associated with an elevated maternal serum alpha-fetoprotein level. Physicians counseling patients with unexplained elevated maternal serum alpha-fetoprotein levels should include placenta accreta or percreta in the differential diagnosis and should maintain an awareness of its existence in patients with acute abdomen in pregnancy.